Cellulosic material and method for making same



Patented Feb. 9, 1937 Winfield Walter Becker-t, Ardentown, DeL, as-

signor, by me'sne assignments, to E. I. du Pont de, Nemours & Company, Wilmington, DeL, a

' corporation of Delaware No Drawing.

Application September 15, 1934,

Serial No. 144,251 10 Claims. c1. 106-40) This invention relates to cellulosic structures such as filaments, threads, fabrics, sheets, films, caps, tubing, or the like. More particularly, this invention relates to cellulosic structures of the type just mentioned having a subdued or low luster or that are more or less opaque.

In the ordinary methods of preparing cellulosic structures, such as filaments, threads, films, caps, tubing, etc., from viscose, cuprammonium, nitrocellulose, cellulose acetate and other cellulosic solutions (without the addition of opaquing or low luster-inducing agents to the solution), the products are transparent or translucent and very highly lustrous. For many purposes, transparency, brilliant sheen and luster are not desirable and thus restrict the uses of the materials. Re-

cently, various methods have been proposed for producing cellulosic structures having a low or subdued luster or opacity.

I have found that I can produce cellulosic structures characterized by a low luster or opacity by incorporating thereina substituted amide of the character described in detail hereinafter which imparts opacity or low luster by remaining in the cellulosic structure.

An object of the invention comprises the production of new opacified or low luster cellulosic structures. relates to the production of novel cellulosic struc- .ures containing organic compounds which remain in the finished article and which impart opacity or low luster. Other objects of the invention will appear hereinafter.

The objects of the invention are accomplished in general by incorporating in the cellulosic solution from which the structure is to be produced an opaquing or a low luster-inducing agent of the type hereinafter more fully explained.

The low luster-inducing agent contemplated by this invention is an organic compound of high molecular weight having two or more nuclei highly deficient in hydrogen, said compound being an amide of an acid taken from the group consisting of carboxylic, aryl and alkyl sulfonic and sulfinic acids, and their colorless --R, O-R, -S- -R, -Se-,R., -Te-R, -NHR, --NR2, COR, -SO2R, SOR, hydroxy, alkyl and halogen derivatives, in which R may be alkyl, aryl, alkaryl, aralky1,or an heterocyclic group, the nitrogen of the amido group being completely substituted, and in which no carbon atom is common to more than one amido nitrogen. These organic compounds will hereinafter be referred to as substituted amides.

So far as the instant invention is concerned,

A further object of the invention each'closedchain of carbon or, hetero atoms or combination of carbon and heteroatoms will be considered a nucleus. Thus, benzene, naphthalene and carbazole have one, two and three nuclei respectively.

These opaquing or low luster-inducing agents, which are preferably white in color, possess a sufliciently low vapor pressure and are sumciently inert to resist the change or removal from the cellulosic structure in the ordinary process of making and finishing the same during the manufacture thereof. They also efiectively resist removal or change during any of the usual processes to which the finished cellulosic structure may be subjected, such as boiling-off, dyeing, bleaching, washing, ironing, etc. These substances are incompatible with the mass of the substances constituting the final product. They may be soluble, but, in the preferred embodiment of this invention, they are insoluble in the solution from which the structure is prepared.

Highly effective delusterants function in particular by reason of their opacifying power which is a function of the difference in refractive index between the delusterant particle and the surrounding medium. Those in my preferred range differ from the index of the medium by 'at least 0.10 and the greater this difference, the more effective the compound as an opacifler and/or delusterant. Most organic compounds have several indexes and the statement just made refers to the highest index of the compound or to any one of the several indexes.

As illustrative examples of substituted amides coming within the scope of this invention are the following:

Diphenyl benzamide (M. I. 177 0.)

Di-alpha-naphtbyl benzamide aoeasos stability, acid insolubility andeifectiveness are I the following:

Diphenyl benzamide Benzoyl di-beta-naphthyl amine Symmetrical dibenzoyl-di-beta-naphthyl ethylene diamine uct. Cellulosic structures containing these low luster-inducing or opaquing agents in amounts ranging from 0.10-20.0% by weight have given satisfactory results, but, of course, it is obvious that smaller or larger quantities may be employed as desired. When a viscose solution is employed, satisfactory results may be secured if it contains 7% cellulose and from 0.01-l.5% more or less of the low luster-inducing or opaquing agent.

If desired, the low luster-inducing agents contemplated by the instant invention may be used in combination with each other or with other low luster-inducing agents, such as mineral oil, petroleum jelly, waxes, paraflin, benzene, toluene, pine oil or inorganic pigments, such as titanium oxide. lithopone, zinc sulfide, etc.

The low luster-inducing agent may be added to the solution at any stage in the course of the manufacture thereof, or after the preparation of the solution and prior to the spinning, extrusion or casting operation. It may be added directly, if the particle size is satisfactory, or after suitable adjustment of the particle size by any of the well known methods, such as emulsiflcation, grinding in a colloid mill or pebble mill, or in the form of a suspension or emulsion prepared with or without the assistance of suitable dispersing agents or protective colloids, such as soaps, sulfonated oils, alkyl naphthalene sulfonates, sodium caseinate, etc. or combinations thereof.

In order to more fully explain the principles of this invention, the following illustrative ex- -amples are given.

Example L-F'our hundred parts of .diphenyl benzamide (melting point 177 are ground with 600 parts of water, 8 parts of sodium caseinate and 4,000 parts of pebbles in a'pebble mill until the particles have been reduced to a particle size below 4 microns in diameter. used in making up viscose in such proportions that 0.5 per cent of diphenyl benzamide is incorporated in viscose containing 7 per cent cellulose. This viscose is spun into filaments or cast into sheets in the usual manner. The resulting rayon has a very desirable low luster. Films prepared in this manner are characterized by a desirable opacity.

Example II .-Four hundred parts of symmetrical dibenzoyi-di-beta-naphthyl ethylene diamine are processed in the same manner as described in the previous example. The products have a much lower luster than can be obtained with mineral oil, resembling those obtained with white pigments, such as T102.

Example III.Four hundred parts of benzoyldi-beta-naphthylamine (melting point 173) are processed in the same manner as described in Example I, added to viscose in the proportion of 0.1 per cent. The rayon spun from such a viscose has a moderate low luster It is to be understood that these examples do not'in any way restrict the inventionthereto but This dispersion is merely illustrate several specific and preferred embodiments which have given satisfactory results.

Though the preferred embodiments of this invention contemplate the incorporation of the low luster-inducing agent in the solution at some time prior to the extrusion or castingthereof, satisfactoryresults may be secured also by applying the ganic solvents, it is only necessary that a suitable choice of amide be made so that the solubility characteristics do not interfere. It has already been pointed out that the low luster-inducing substance must be incompatible with the mass of substance constituting the final product. In addition, in the case of cellulose acetate or nitrate spinning solutions, it is preferable that the low luster-inducing substance be insoluble in the solvent employed. However, resinous materials and certain crystallized substances, soluble in the solvent, precipitate, upon evaporation of the solvent, in the cellulose acetate in the form of fine amorphous or crystalline particles sufiiciently small and well distributed to avoid harmful effect on the physical properties of the resulting structure. The advantage in such cases lies in avoiding the necessity for emulsifying or grinding the compounds to obtain suitable subdivision. Suitable compounds may be readily selected from any specific system by one skilled in the art.

While the invention has been described generally with respect to the use of the various compounds mentioned herein in opaquing cellulosic structures prepared by casting or spinning methods, it is desired to emphasize the fact that these compounds are of special benefit in the spinning of artificial silk. Thus, undelustered artificial silk has a shade and luster which is undesired for a great many purposes. present invention, it is possible to produce artificial silk, particularly of the regenerated cellulose type prepared from viscose or cuprammonium cellulose, having a pleasing dull appearance, the dullness being of any degree desired, in which the opaquing or delustering agent is uniformly distributed and which does not interfere with the tenacity of the yarn to any large extent.

Since it is obvious that various changes and modifications may be made in the above description without departing from the nature or spirit thereof, this invention is not restricted thereto except as set forth in the claims.

I claim:

l. Delustered artificial cellulosic articles containing, in a phase distinct from that of the cellulosic material therein, a finely divided organic compound having two or more nuclei highly deficient in hydrogen, said compound being an amide of an acid taken from the group consisting of carboxylic, aryl and alkyl sulfonic and sulfinic acids, the nitrogen of any amido group being completely substituted and in which no carbon atom is common to more than one amido nitrogen.

In accordance with the 2. Delustered artificial cellulosic articles containing, in a phase distinct from that of the cel1ulosic material therein, 0.1 to 20% of a finely divided organic compound having two or more nuclei highly deficient in hydrogen, said compound being an amide of an acid taken from the group consisting of carboxylic, aryl and alkyl sulfonic and sulfinic acids, the nitrogen of any amido group being completely substituted and in which no carbon atom is common to more than one amido nitrogen.

3. Delustered artificial cellulosic articles containing, in a phase distinct from that of the cellulosic material therein, 0.1 to 20% finely divided diphenyl benzamlde.

4. Delustered artificial cellulosic articles containing-in a phase distinct from that of the cellulosic material therein, 0.1 to 20% finely divided benzoyl-di-beta-naphthyl amine.

5. Delustered artificial cellulosic articles containing, in a phase distinct from that of the cellulosic material therein, 0.1 to 20% finely divided symmetrical dibenzoyldi-beta-naphthyl ethylene diamine.

6. An artificial thread comprising regenerated cellulose having diphenyil benzamide incorporated therein in finely divided form.

7. An artificial thread comprising regenerated cellulose having benzoyl-di-beta-naphthyl amine incorporated therein in finely divided form.

8. An artificial thread comprising regenerated cellulose having symmetrical dibenzoyl-di-betanaphthyl ethylene diamine incorporated therein in finely divided form.

9. An artificial thread comprising regenerated cellulose and a low luster-inducing agent, said agent comprising an incompatible, finely divided organic compound having two or more nuclei highly deficient in hydrogen, said compound being an amide of an acid taken from the group consisting of carbocyclic, aryl and alkyl sulfonic and sulfinic acids, the nitrogen of any amido group being completely substituted and in which no carbon atom is common to more than one amide nitrogen.

10. Delustered artificial cellulosic articles containing, in a phase distinct from that of the cellulosic material therein, a finely divided organic compound having at least two carbocyclic or heterocyclic nuclei highly deficient in hydrogen and at least one amido group, any amido group in said compound being completely substituted, said compound having not more than one amido group common to any carbon atom.

WINFIELD WALTER HECKERT. 

